CN110494654B

CN110494654B - Telecentric fan, molding die and fluid delivery device

Info

Publication number: CN110494654B
Application number: CN201780089424.1A
Authority: CN
Inventors: 公文由衣; 大塚雅生
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2017-04-10
Filing date: 2017-08-31
Publication date: 2021-09-14
Anticipated expiration: 2037-08-31
Also published as: CN110494654A; TWI661131B; JP6951428B2; JPWO2018189931A1; WO2018189931A1; TW201837322A

Abstract

The telecentric fan (10) comprises a front blade body (21A) and a rear blade body (21B). A minimum distance from an arbitrary position on a negative pressure surface of a front blade body (21A) to a positive pressure surface of a rear blade body (21B) is defined as an inter-blade distance, a position on the negative pressure surface in a maximum thickness portion of the front blade body (21A) is defined as a maximum thickness position (P2), a range between the maximum thickness position (P2) and a front edge portion (26) is defined as an inner diameter side negative pressure surface (24A), a range between the maximum thickness position (P2) and a rear edge portion (27) is defined as an outer diameter side negative pressure surface (24B), and a length from the front edge portion to the rear edge portion in the negative pressure surface of the front blade body (21A) is defined as a negative pressure surface length. The inter-blade distance on the inner diameter side negative pressure surface is longer than the inter-blade distance at the maximum thickness position. The distance between the blades in the range between the maximum thickness position and a position separated from the maximum thickness position by more than half of the length of the suction surface is approximately constant. The separation of fluid from the blade body is suppressed, and the performance and noise are improved.

Description

Telecentric fan, molding die and fluid delivery device

Technical Field

The technology disclosed in this specification relates to a telecentric fan, a molding die, and a fluid delivery device. The present application claims the priority of japanese patent application No. 2017-077580, which is based on the application filed on 10.4.2017. All the descriptions described in the japanese patent application are incorporated in the present specification by reference.

Background

There are cases where a plurality of blades (blades) having the same size and the same shape are arranged linearly or circularly at equal intervals and in the same posture. The blade body configured as described above is referred to as a blade row. In the wing row, two types of the decelerating wing row and the accelerating wing row are largely classified.

Referring to fig. 34, the so-called deceleration vane row is used for a compressor, a fan, a pump, and the like, for decelerating a fluid and increasing a pressure. In the deceleration row shown in fig. 34, a plurality of blades are arranged at intervals D. The velocity WA is reduced to the velocity WB by the expansion of the flow path, and the kinetic energy is effectively recovered as a pressure (supercharging action). When the steering angle is θ and the angle between the blade row and the normal line of the fluid is λ, for example, WA > WB and λ > θ/2 are used for the supercharging action of the decelerating blade row.

On the other hand, referring to fig. 35, a so-called speed-increasing blade row increases the speed of the fluid and decreases the pressure, and is used in a turbine, a wind turbine, or the like. In the speed increasing blade row shown in fig. 35, the speed is increased from the speed WA to the speed WB. In the acceleration action of the acceleration wing row, WA < WB, and λ < θ/2, for example. In the wing rows described above, the following equation (1) holds true, and when the pressure loss does not substantially occur, the amount of change in pressure is expressed by the following equation (2).

WB/WA ═ cos λ/cos (θ - λ) … formula (1)

P2－P1＝ρ(WA²－WB²) /2 … formula (2)

As disclosed in

patent documents

1 and 2, a telecentric fan is known. Telecentric fans are generally deceleration rows of wings due to their principle of operation. Specifically, in the telecentric fan, a plurality of blades are arranged in a circular shape at equal intervals. As the fan rotates, fluid flows into the vicinity of the center of rotation and flows out from the outer periphery of the fan. The length in the circumferential direction is increased in proportion to the distance from the position of the center of rotation (as the diameter is increased). The flow path formed between the blade bodies adjacent to each other (i.e., the inter-blade space) gradually increases from the center of the fan toward the radially outer side.

When the flow path is enlarged, the flow velocity of the fluid flowing through the flow path is decelerated in inverse proportion to the enlargement of the flow path (mass conservation law). Therefore, the plurality of blade bodies in the telecentric fan are generally deceleration wing rows. Examples of the blade body of the telecentric fan generally used in the past include a circular arc blade, a flat blade, and a wing blade. The telecentric fan using these general blade bodies as the blade row is a decelerating blade row for the above reasons.

Patent document 1: japanese patent No. 5469635.

Patent document 2: japanese patent laid-open No. 2005-016315.

The flow velocity of the fluid flowing between the blades of the telecentric fan decreases as the fluid moves radially outward. The kinetic energy included in the fluid decreases in proportion to the square of the decrease in the flow velocity. When the kinetic energy included in the fluid is at a disadvantage with respect to the negative pressure acting on the blade body, the fluid peels off from the blade body, the performance as the blade body is reduced, and the noise is increased. Since a conventional blade body used in a telecentric fan often has a shape or a size mainly for the purpose of overcoming high pressure loss, peeling of fluid and increase of noise may be easily caused.

The present specification discloses a telecentric fan capable of improving performance and reducing noise by suppressing peeling of fluid from a blade body, a molding die used for manufacturing the telecentric fan, and a fluid delivery device including the telecentric fan.

A telecentric fan according to a first aspect disclosed in the present specification includes a plurality of blade bodies having a leading edge portion into which air flows and a trailing edge portion from which air flows, and disposed at intervals in a circumferential direction; a plurality of blade bodies each having an airfoil surface extending between the leading edge portion and the trailing edge portion and including a positive pressure surface on a side of the blade body in a rotational direction and a negative pressure surface on an opposite side of the blade body in the rotational direction; the plurality of blade bodies include a front-side blade body and a rear-side blade body that faces the front-side blade body with the gap therebetween and is located on the opposite side of the rotation direction with respect to the front-side blade body; when a shortest distance from an arbitrary portion on a negative pressure surface of the front blade body to a positive pressure surface of the rear blade body is defined as an inter-blade distance in the portion, the front blade body has a maximum thickness portion that specifies a maximum thickness in the front blade body, a position on the negative pressure surface in the maximum thickness portion is defined as a maximum thickness position, a range between the maximum thickness position and the leading edge portion in the negative pressure surface of the front blade body is defined as an inner diameter side negative pressure surface, a range between the maximum thickness position and the trailing edge portion in the negative pressure surface of the front blade body is defined as an outer diameter side negative pressure surface, a length from the leading edge portion to the trailing edge portion in the negative pressure surface of the front blade body is defined as a negative pressure surface length, the inter-blade distance in the inner diameter side negative pressure surface is longer than the inter-blade distance in the maximum thickness position, the distance between the blades in the range between the maximum thickness position and a position spaced apart from the maximum thickness position by at least half of the length of the suction surface is substantially constant.

A telecentric fan according to a second aspect disclosed in the present specification includes a plurality of blade bodies having a leading edge portion into which air flows and a trailing edge portion from which air flows, and disposed at intervals in a circumferential direction; a plurality of blade bodies each having an airfoil surface extending between the leading edge portion and the trailing edge portion and including a positive pressure surface on a side of the blade body in a rotational direction and a negative pressure surface on an opposite side of the blade body in the rotational direction; each of the plurality of blade bodies includes an inner diameter side blade portion including the leading edge portion, and an outer diameter side blade portion located radially outward of the inner diameter side blade portion and including the trailing edge portion; the inner diameter side blade portion includes: a maximum thickness portion that defines a maximum thickness among the inner diameter side blade portions; an enlarged portion located between the leading edge portion and the maximum thickness portion, the enlarged portion gradually increasing in thickness from the leading edge portion side toward the radially outer side; and a reduced portion located radially outward of the maximum thickness portion, the reduced portion gradually decreasing in thickness from the side of the maximum thickness portion toward the radially outward; a negative pressure surface of the inner diameter side blade and a positive pressure surface of the inner diameter side blade each having a surface shape curved in a convex shape toward the opposite side of the rotation direction; a curvature of a negative pressure surface of the inner diameter side blade portion is larger than a curvature of a positive pressure surface of the inner diameter side blade portion; the outer diameter side blade section includes a plate-shaped section extending from the trailing edge section side to the radially inner side with substantially the same blade thickness; the curvature of the negative pressure surface of the plate-shaped portion and the curvature of the positive pressure surface of the plate-shaped portion are both smaller than the curvature of the negative pressure surface of the inner diameter side blade portion.

In the above telecentric fan, the following may be used: a pressure surface of the inner diameter side blade section and a pressure surface of the outer diameter side blade section are tangent to each other; the suction surface of the inner diameter side blade and the suction surface of the outer diameter side blade are tangent to each other.

In the above telecentric fan, the following may be used: a maximum thickness of the outer diameter side blade portion is smaller than a maximum thickness of the inner diameter side blade portion; the camber of the outer diameter side blade portion is smaller than the camber of the inner diameter side blade portion.

In the above telecentric fan, the following may be used: a through hole extending in a direction parallel to the rotation axis is provided in the inner diameter side blade portion; the through-hole may be formed to include the maximum thickness portion, or may be formed to be one each on the inside in the radial direction and the outside in the radial direction of the maximum thickness portion.

In the above telecentric fan, the following may be used: when the inner peripheral surface of the inner diameter side blade portion in which the through hole is formed is viewed in a direction parallel to the rotation axis, the inner peripheral surface takes a crescent Moon (crescent Moon) shape.

In the above telecentric fan, the following may be used: when a straight line connecting the leading edge portion and the trailing edge portion is defined as a chord line, a length of the chord line is defined as C, a length of a perpendicular line extending from a negative pressure surface of the blade body to a position where the length of the perpendicular line extending to the chord line is the maximum is defined as t, and a value of t/C is defined as a camber ratio m, the camber ratio m is set to 0.25 or more for each of the plurality of blade bodies.

In the above telecentric fan, the following may be used: the plurality of blade bodies are configured to form a constant velocity row.

The telecentric fan may be formed of a resin.

The molding die disclosed in the present specification is used for molding the telecentric fan disclosed in the present specification.

The fluid transport device disclosed by the present specification includes a blower including the telecentric fan disclosed by the present specification and a drive motor coupled to the telecentric fan and configured to rotate the plurality of blade bodies.

According to the telecentric fan having the above configuration, the flow path between the adjacent blades in the rotational direction is formed so as to extend with a substantially constant flow path cross-sectional area from the center side of the telecentric fan toward the outer side in the radial direction, and the flow velocity of the fluid flowing between the adjacent blades in the rotational direction is always substantially constant even if the fluid advances from the center side of the telecentric fan toward the outer side in the radial direction. Even if the fluid travels outward in the radial direction, the decrease in the flow velocity and the decrease in the kinetic energy included in the fluid can be suppressed. This can significantly lengthen the limit (margin) in time and distance until the kinetic energy included in the fluid becomes a disadvantage with respect to the negative pressure acting on the blade body. The separation of the fluid from the blade body can be suppressed, and as a result, the occurrence of noise due to the separation can be greatly reduced while suppressing the performance degradation of the blade body.

Drawings

Fig. 1 is a perspective view showing a telecentric fan 10 according to the first embodiment.

Fig. 2 is a front view of the telecentric fan 10 according to the first embodiment.

Fig. 3 is an enlarged front view showing an area surrounded by a line III in fig. 2.

Fig. 4 is an enlarged front view of a portion of the telecentric fan 10 shown in fig. 3.

Fig. 5 is a front view of a telecentric fan 10A according to the second embodiment.

Fig. 6 is an enlarged front view showing an area surrounded by the VI line in fig. 5.

Fig. 7 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10A shown in fig. 6.

Fig. 8 is a perspective view showing a telecentric fan 10B according to the third embodiment.

Fig. 9 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10B shown in fig. 8.

Fig. 10 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10C according to the third modification of the embodiment.

Fig. 11 is an enlarged front view of a part (blade body 21) of the telecentric fan 10D according to the fourth embodiment.

Fig. 12 is an enlarged front view of a part (blade body 21) of the telecentric fan 10E according to the fourth modification 1 of the embodiment.

Fig. 13 is an enlarged front view of a part (blade body 21) of the telecentric fan 10F according to the fourth modification example 2 of the embodiment.

Fig. 14 is a sectional view showing a molding die 110 used for manufacturing the telecentric fan 10 according to the fifth embodiment.

Fig. 15 is a cross-sectional view showing a blower 120 using the telecentric fan 10 according to the fifth embodiment.

Fig. 16 is a cross-sectional view showing a cross-sectional shape of blower 120 along line XVI-XVI in fig. 15.

Fig. 17 is a sectional view showing an air cleaner 140 using the telecentric fan 10 according to the fifth embodiment.

Fig. 18 is an enlarged front view of a part (blade body 21) of the telecentric fan according to the experimental example.

Fig. 19 is a table showing experimental conditions and experimental results for the experimental examples.

Fig. 20 is an enlarged front view of a part (blade body 21) of the telecentric fan 10S1 according to experimental example 1.

Fig. 21 is an enlarged front view of a part (blade body 21) of the telecentric fan 10S5 according to experimental example 5.

Fig. 22 is an enlarged front view of a part (blade body 21) of the telecentric fan 10S9 according to experimental example 9.

Fig. 23 is a graph showing a relationship between the camber ratio m and the air volume as a result of an experiment concerning an experimental example.

Fig. 24 is a graph showing a relationship between the camber ratio m and noise as a result of an experiment concerning an experimental example.

Fig. 25 is a graph showing a relationship between the camber ratio m and the power consumption as a result of an experiment concerning an experimental example.

Fig. 26 is a graph showing the relationship between the maximum blade thickness and the air volume as a result of the experiment concerning the experimental example.

Fig. 27 is a graph showing the relationship between the maximum wing thickness and the noise as a result of the experiment concerning the experimental example.

Fig. 28 is a graph showing the relationship between the maximum thickness and the power consumption as a result of an experiment concerning an experimental example.

Fig. 29 is a graph showing the relationship between the blade thickness ratio and the air volume as a result of the experiment concerning the experimental example.

Fig. 30 is a graph showing the relationship between the blade thickness ratio and noise as a result of an experiment concerning an experimental example.

Fig. 31 is a graph showing the relationship between the thickness ratio and the power consumption as a result of an experiment concerning an experimental example.

Fig. 32 is an enlarged front view of a part (blade body 21) of the telecentric fan 10S7 according to experimental example 7.

Fig. 33 is an enlarged front view of a part (blade body 21) of the telecentric fan 10S7a according to experimental example 7.

Fig. 34 is a sectional view showing a plurality of blade bodies configured to become a decelerating row.

Fig. 35 is a sectional view showing a plurality of blade bodies configured to become a speed increasing row.

Detailed Description

The embodiments will be described below with reference to the drawings. The same reference numerals are given to the same components and corresponding components, and the description thereof may not be repeated.

[ first embodiment ]

With reference to fig. 1 to 4, a description will be given of a telecentric fan 10 according to a first embodiment. Fig. 1 and 2 are a perspective view and a front view of a telecentric fan 10, respectively. Referring to fig. 1 and 2, the telecentric fan 10 includes a plurality of blade bodies 21. The telecentric fan 10 has a substantially cylindrical outer appearance as a whole, and the plurality of blade bodies 21 are disposed on the substantially cylindrical side surface. The telecentric fan 10 is integrally formed of resin and rotates in the direction indicated by the arrow 103 around a virtual rotation axis 101.

The telecentric fan 10 sends out the air taken in from the inner periphery side to the outer periphery side by the plurality of rotating blade bodies 21. The telecentric fan 10 sends out air from the rotational center side to the outside in the radial direction by a centrifugal force. The telecentric fan 10 functions as a Sirocco fan (Sirocco fan), is mounted on a household electrical appliance or the like, and can be used with a rotation number in a low Reynolds number region.

The telecentric fan 10 further has

peripheral frames

12, 13. The outer

peripheral frames

12 and 13 are formed to extend annularly around the rotation shaft 101. The outer frames 12 and 13 are arranged at a distance in the axial direction of the rotating shaft 101. A boss portion 16 for coupling the telecentric fan 10 to the drive motor is integrally formed on the outer peripheral frame 13. The boss portion 16 is made of, for example, a rubber component and a metal component, and is integrated with the outer peripheral frame 13 by insert molding.

The plurality of blade bodies 21 are provided at intervals in the circumferential direction around the rotation shaft 101. The plurality of blade bodies 21 are disposed at equal intervals in the circumferential direction around the rotating shaft 101, and are supported by the outer peripheral frame 12 and the outer peripheral frame 13 at both ends in the axial direction of the rotating shaft 101. The blade body 21 is erected on the outer peripheral frame 13, and is formed to extend in the axial direction of the rotary shaft 101 toward the outer peripheral frame 12.

Fig. 3 is an enlarged front view showing an area surrounded by a line III in fig. 2, and fig. 4 is an enlarged front view showing a part of the telecentric fan 10 shown in fig. 3. Fig. 3 and 4 show the shape of the blade body 21 when viewed from a direction parallel to the rotation axis 101 (fig. 1 and 2) of the telecentric fan 10.

As shown in fig. 3 and 4, the plurality of blade bodies 21 have the same shape. Each of the plurality of blade bodies 21 has the same airfoil sectional shape even when cut at any position in the axial direction of the rotary shaft 101.

The blade body 21 has a leading edge portion 26 located at an end portion on the inner circumferential side of the blade body 21 and into which air flows during rotation, and a trailing edge portion 27 located at an end portion on the outer circumferential side of the blade body 21 and out of which air flows during rotation. The blade body 21 is formed to be inclined from the front edge portion 26 toward the rear edge portion 27 in the circumferential direction around the rotation axis 101. The blade body 21 is formed to be inclined from the front edge portion 26 toward the rear edge portion 27 in the rotation direction of the telecentric fan 10.

The blade body 21 is formed with a blade surface 23 including a positive pressure surface 25 and a negative pressure surface 24. The positive pressure surface 25 extends between the leading edge portion 26 and the trailing edge portion 27 and is located on the rotation direction side of the blade body 21. The negative pressure surface 24 extends between the leading edge portion 26 and the trailing edge portion 27, and is located on the opposite side of the blade body 21 in the rotation direction (the back side of the positive pressure surface 25). During rotation of the telecentric fan 10, a pressure distribution is generated which is relatively large at the positive pressure surface 25 and relatively small at the negative pressure surface 24, accompanied by the generation of air flow (airflow) over the airfoil 23.

The plurality of blade bodies 21 include a front blade body 21A and a rear blade body 21B. The front blade body 21A and the rear blade body 21B have the same shape and size. The rear blade body 21B faces the front blade body 21A with a gap therebetween, and is located on the opposite side of the rotation direction (arrow 103) with respect to the front blade body 21A.

A shortest distance from an arbitrary portion on the negative pressure surface 24 (a portion surrounded by a broken line 24R in fig. 4) of the front blade body 21A to the positive pressure surface 25 (a portion surrounded by a broken line 25R in fig. 4) of the rear blade body 21B is defined as an inter-blade distance at the arbitrary portion. For example, the distances L1 to L6 between the portions P1 to P6 on the negative pressure surface 24 of the front blade body 21A are respectively defined.

The front blade body 21A has a maximum thickness portion (a portion indicated by an arrow H) that defines the maximum thickness of the front blade body 21A. The maximum thickness portion is defined to include two intersection points of an intersection point of the inscribed circle and the negative pressure surface 24 and an intersection point of the inscribed circle and the positive pressure surface 25, when a circle having a maximum size is drawn between the negative pressure surface 24 and the positive pressure surface 25, out of circles inscribed in the negative pressure surface 24 and the positive pressure surface 25. The portion P2 corresponds to a position on the negative pressure surface 24 in the maximum thickness portion (hereinafter referred to as a maximum thickness position P2).

The range between the maximum thickness position P2 and the leading edge portion 26 in the suction surface 24 of the front blade body 21A is defined as the inner diameter side suction surface 24A. The range between the maximum thickness position P2 and the trailing edge portion 27 in the suction surface 24 of the front blade body 21A is defined as the outer diameter side suction surface 24B. Further, a length from the leading edge portion 26 to the trailing edge portion 27 (a length of a portion surrounded by a broken line 24R in fig. 4) in the negative pressure surface 24 of the front blade body 21A is defined as a negative pressure surface length 24L. The suction surface length 24L is a sum of the length of the inner diameter side suction surface 24A and the length of the outer diameter side suction surface 24B.

In the telecentric fan 10 of the present embodiment, the inter-blade distance on the inner diameter side negative pressure surface 24A is configured to be longer than the inter-blade distance L2 at the maximum thickness position P2. The inter-blade distance L1 at an arbitrary position P1 between the maximum thickness position P2 and the leading edge 26 is configured to be longer than the inter-blade distance L2 at the maximum thickness position P2. In the present embodiment, the inter-blade distance gradually increases as the distance from the maximum thickness position P2 approaches the leading edge portion 26.

The inter-blade distance in the range between the maximum thickness position P2 and a position spaced apart from the maximum thickness position P2 by a length equal to or more than half the suction surface length 24L in the outer diameter side suction surface 24B is configured to be substantially constant. The substantially constant means that the inter-blade distance is included within a range of at least ± 25% of the inter-blade distance L2 at the maximum thickness position P2, preferably within a range of ± 15% of the inter-blade distance L2 at the maximum thickness position P2, and more preferably within a range of ± 10% of the inter-blade distance L2 at the maximum thickness position P2.

In the telecentric fan 10 of the present embodiment, the inter-blade distance L2 at the maximum thickness position P2, the inter-blade distance L3 at the position P3, and the inter-blade distance L4 at the position P4 are the same. In the outer diameter side negative pressure surface 24B, the distance between the blades gradually decreases as the distance from the point P4 to the point P5 ranges between the point P4 and the point P5. The distance between wings L5 at the point P5 and L6 at the point P6 are the same.

Specifically, the negative pressure surface length 24L was 28.3mm, the inter-blade distances (L2 to L4) at the maximum thickness position P2 and the positions P3 and P4 were 3.6mm, and the inter-blade distances (L5 and L6) at the positions P5 and P6 were 3.4 mm. The distance between the maximum thickness position P2 and the position separated from the maximum thickness position P2 toward the rear edge 27 by 21.4mm in length is substantially constant.

(action and Effect)

When the telecentric fan 10 is rotated, as indicated by an arrow 102 in fig. 1, an air flow is generated which flows in from the leading edge portion 26, passes over the airfoil 23, and flows out from the trailing edge portion 27. The telecentric fan 10 of the present embodiment includes a plurality of blade bodies 21 satisfying the inter-blade distance described above. The flow paths between the blade bodies 21 adjacent in the rotational direction are formed to extend with a substantially constant flow path cross-sectional area from the center side of the telecentric fan 10 toward the radially outer side. The flow velocity of the fluid flowing between the blade bodies 21 adjacent in the rotational direction is always substantially constant even if the fluid travels radially outward from the center side of the telecentric fan 10.

The plurality of blade bodies 21 in the present embodiment constitute a constant velocity row different from the decelerating row or the accelerating row. Even if the fluid travels outward in the radial direction, the decrease in the flow velocity and the decrease in the kinetic energy included in the fluid can be suppressed. This can significantly increase the time and distance limit until the kinetic energy included in the fluid becomes inferior to the negative pressure acting on the blade body 21. The separation of the fluid from the blade body 21 can be suppressed, and as a result, the occurrence of noise due to the separation suppression can be greatly reduced while suppressing the performance degradation of the blade body 21.

[ second embodiment ]

With reference to fig. 5 to 7, a description will be given of a telecentric fan 10A according to a second embodiment. Fig. 5 is a front view showing the telecentric fan 10A. Fig. 6 is an enlarged front view showing an area surrounded by line VI in fig. 5, and fig. 7 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10A shown in fig. 6.

As shown in fig. 5, the telecentric fan 10A according to the second embodiment has a substantially cylindrical outer appearance as a whole, and the plurality of blades 21 are disposed on the substantially cylindrical side surface, as in the telecentric fan 10 (fig. 2) according to the first embodiment. The telecentric fan 10A is integrally formed of resin and rotates in the direction indicated by the arrow 103 around a virtual rotation axis 101. The telecentric fan 10 according to the first embodiment is different from the telecentric fan 10A according to the second embodiment in the following points.

As shown in fig. 6 and 7, each of the plurality of blade bodies 21 has an inner diameter side blade portion 21M including a leading edge portion 26 and an outer diameter side blade portion 21N including a trailing edge portion 27. The outer diameter side blade 21N is located radially outward of the inner diameter side blade 21M. The inner diameter side blade portion 21M of the present embodiment is a portion of the blade body 21 surrounded by the leading edge portion 26 and the points P10 to P12.

The inner diameter side blade portion 21M includes a maximum thickness portion 21Ma, an enlarged portion 21Mb, and a reduced portion 21 Mc. The maximum thickness portion 21Ma is a portion defining the maximum thickness h2 in the inner diameter side blade portion 21M. The maximum thickness h2 is, for example, 3.6 mm. The point P11 indicates a position on the negative pressure surface 24 in the maximum thickness portion 21 Ma.

The enlarged portion 21Mb is a portion of the inner diameter side blade portion 21M on the side of the leading edge portion 26 with respect to the maximum thickness portion 21 Ma. The enlarged portion 21Mb is located between the leading edge 26 and the maximum thickness portion 21Ma, and the thickness h1 (fig. 6) of the enlarged portion 21Mb is configured to gradually increase from the leading edge 26 side toward the radially outer side.

The reduced portion 21Mc is a portion of the inner diameter side blade portion 21M that is radially outward of the maximum thickness portion 21 Ma. The reduced portion 21Mc is located between the maximum thickness portion 21Ma and the outer diameter side blade portion 21N, and the thicknesses h3, h4 of the reduced portion 21Mc are configured to gradually become thinner from the maximum thickness portion 21Ma side toward the outer radial direction.

Both the negative pressure surface 24M of the inner diameter side blade portion 21M and the positive pressure surface 25M of the inner diameter side blade portion 21M have a surface shape curved in a convex shape toward the opposite side of the rotation direction (arrow 103 shown in fig. 6). The curvature of the negative pressure surface 24M of the inner diameter side blade portion 21M is larger than the curvature of the positive pressure surface 25M of the inner diameter side blade portion 21M.

The outer diameter side blade portion 21N includes a plate-like portion 21Np extending from the side of the rear edge portion 27 to the radially inner side with substantially the same blade thicknesses h6, h5 (fig. 6). The thicknesses h6, h5 are, for example, 1.0 mm. The curvature of the negative pressure surface 24Np of the plate-shaped portion 21Np and the curvature of the positive pressure surface 25Np of the plate-shaped portion 21Np are both smaller than the curvature of the negative pressure surface 24M of the inner diameter side blade portion 21M.

(action and Effect)

When the telecentric fan 10A is rotated, an air flow is generated which flows in from the leading edge portion 26, passes over the airfoil 23, and flows out from the trailing edge portion 27. The telecentric fan 10A of the present embodiment includes a plurality of blade bodies 21 satisfying the blade thickness and curvature described above. The flow paths between the blade bodies 21 adjacent in the rotational direction are formed to extend with a substantially constant flow path cross-sectional area from the center side of the telecentric fan 10A toward the radially outer side. The flow velocity of the fluid flowing between the blade bodies 21 adjacent in the rotational direction is always substantially constant even if the fluid advances radially outward from the center side of the telecentric fan 10A.

The plurality of blade bodies 21 in the present embodiment also constitute a constant velocity row different from the decelerating row or the accelerating row. Even if the fluid travels outward in the radial direction, the decrease in the flow velocity and the decrease in the kinetic energy included in the fluid can be suppressed. This can significantly increase the time and distance limit until the kinetic energy included in the fluid becomes inferior to the negative pressure acting on the blade body 21. The separation of the fluid from the blade body 21 can be suppressed, and as a result, the occurrence of noise due to the separation suppression can be greatly reduced while suppressing the performance degradation of the blade body 21.

[ modification 1 of the second embodiment ]

Referring to fig. 7, as a preferred embodiment, the positive pressure surface of the inner diameter side blade portion 21M and the positive pressure surface of the outer diameter side blade portion 21N are tangent to each other at the point P10 to be smoothly connected to each other, and the negative pressure surface of the inner diameter side blade portion 21M and the negative pressure surface of the outer diameter side blade portion 21N are tangent to each other at the point P12 to be smoothly connected to each other. According to the above configuration, when the air flows between the blade bodies 21 adjacent in the rotational direction, the lift force is effectively generated in the air flow, and thereby the performance as the blade body 21 can be further improved.

[ second modification 2 of the second embodiment ]

Referring to fig. 7, as a preferred embodiment, the maximum thickness of the outer diameter side blade portion 21N is smaller than the maximum thickness of the inner diameter side blade portion 21M. Further, it is sufficient if the camber t2 of the outer diameter side blade portion 21N is smaller than the camber t1 of the inner diameter side blade portion 21M. The camber t2 of the outer diameter side blade portion 21N and the camber t1 of the inner diameter side blade portion 21M have values defined below. The point P10 is located between the positive pressure surface of the inner diameter side blade portion 21M and the positive pressure surface of the outer diameter side blade portion 21N in the positive pressure surface 25 of the blade body 21.

A straight line LN1 connecting the leading edge portion 26 and the point P10 in the inner diameter side blade portion 21M is drawn, and the length of a perpendicular line W1 at a position (point P11) where the length of a perpendicular line hanging down from the suction surface in the inner diameter side blade portion 21M to the straight line LN1 is the maximum is defined as the camber t1 of the inner diameter side blade portion 21M. A straight line LN2 connecting the point P10 in the outer diameter side blade portion 21N and the trailing edge portion 27 is drawn, and the length of a perpendicular line W2 at a position P13 where the length of the perpendicular line from the suction surface in the outer diameter side blade portion 21N to the straight line LN2 is maximum is defined as the camber t2 of the outer diameter side blade portion 21N.

According to the above configuration, when the air flows between the blade bodies 21 adjacent in the rotational direction, the lift force is effectively generated in the air flow, and thereby the performance as the blade body 21 can be further improved. As a result, it is possible to suppress the performance degradation of the blade body 21 and also to significantly reduce the occurrence of noise due to the suppression of the separation.

[ third embodiment ]

With reference to fig. 8 and 9, a description will be given of a telecentric fan 10B according to the third embodiment. Fig. 8 is a perspective view showing the telecentric fan 10B. Fig. 9 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10B shown in fig. 8.

As shown in fig. 8, the telecentric fan 10B according to the third embodiment has a substantially cylindrical external appearance as a whole, and the plurality of blade bodies 21 are arranged on the substantially cylindrical side surface, similarly to the telecentric fans 10 (fig. 2) and 10A (fig. 5) according to the first and second embodiments. The telecentric fan 10B is integrally formed of resin and rotates in the direction indicated by the arrow 103 around a virtual rotation axis 101 (fig. 8). The telecentric fan 10A (fig. 5) in the second embodiment is different from the telecentric fan 10B (fig. 8 and 9) in the third embodiment in the following points.

In the telecentric fan 10B, the inner diameter side blade portion 21M (fig. 9) is provided with a through hole 29. The through hole 29 is formed to include the maximum thickness portion 21Ma of the inner diameter side blade portion 21M and extend in a direction parallel to the rotation axis 101 of the telecentric fan 10B.

According to the above configuration, the weight of the blade body 21 can be reduced, and sink marks (sink marks) generated in the thick portion (the vicinity of the maximum thickness portion 21 Ma) of the blade body 21 during molding can be reduced or reduced. Further, imbalance of the telecentric fan 10B during rotation can be significantly suppressed, and vibration noise of the telecentric fan 10B can be further reduced.

[ modification of the third embodiment ]

Fig. 10 is an enlarged front view showing a part (blade body 21) of the telecentric fan 10C according to the third modification of the embodiment. In the telecentric fan 10C, a total of 2 through

holes

29A and 29B are formed in the inner diameter side blade portion 21M. The through

holes

29A and 29B extend in a direction parallel to the rotation axis of the telecentric fan 10C. The through

holes

29A and 29B are formed in the inner diameter blade portion 21M at the radially inner side and the radially outer side of the maximum thickness portion 21 Ma.

According to the above configuration, the weight of the blade body 21 can be further reduced, and sink marks at the time of forming that occur in the thick portion (the vicinity of the maximum thickness portion 21 Ma) of the blade body 21 can be further reduced or reduced. Further, imbalance of the telecentric fan 10C during rotation can be significantly suppressed, and vibration noise of the telecentric fan 10C can be further reduced.

[ other configurations of the first and third embodiments ]

In the third embodiment (fig. 9) and the modification (fig. 10) described above, the inner peripheral surface of the inner diameter side blade portion 21M, in which the through

holes

29, 29A, and 29B are formed, has a circular shape when viewed in a direction parallel to the rotation shaft 101.

The configuration is not limited to the above configuration, and as shown in fig. 3 and 4 in the first embodiment, the inner peripheral surface of the inner diameter side blade portion 21M in which the through hole 29 is formed may have a brow-moon shape when viewed in a direction parallel to the rotation shaft 101. The operation and effect as described in the third embodiment and the modification thereof can be obtained by the crescent-shaped through-hole 29, and the improvement of the appearance as the telecentric fan can be expected.

[ fourth embodiment ]

With reference to fig. 11, a description will be given of a telecentric fan 10D according to the fourth embodiment. Fig. 11 is an enlarged front view of a part (blade body 21) of the telecentric fan 10D.

The telecentric fan 10D according to the fourth embodiment differs from the telecentric fans according to the first to third embodiments in that a concave notch 29C is formed in the telecentric fan 10D instead of the through hole 29 (through

holes

29A and 29B). The notch 29C is different from the through hole 29 in configuration at a point extending from a portion of the positive pressure surface 25 of the inner diameter side blade portion 21M closer to the outer diameter side blade portion 21N in the longitudinal direction to approach the front edge portion 26.

With the above configuration, the weight of the blade body 21 can be further reduced, and sink marks generated in the thick portion (the vicinity of the maximum thickness portion 21 Ma) of the blade body 21 during forming can be further reduced. Further, the unbalance of the telecentric fan 10D during rotation can be greatly suppressed, and the vibration noise of the telecentric fan 10D can be further reduced.

[ modification 1 of the fourth embodiment ]

With reference to fig. 12, a description will be given of a telecentric fan 10E according to a modification 1 of the fourth embodiment. Fig. 12 is an enlarged front view of a part (blade body 21) of the telecentric fan 10E.

The telecentric fan 10E (fig. 12) of the present embodiment is different from the telecentric fan 10D (fig. 11) of the fourth embodiment in that the notch 29C in the telecentric fan 10E includes a portion 29C1 extending from the vicinity of the outer diameter side blade portion 21N in the longitudinal direction of the pressure surface 25 of the inner diameter side blade portion 21M, so as to be close to the leading edge portion 26, and a portion 29C2 extending so as to be away from the leading edge portion 26.

With the above configuration, the weight of the blade body 21 can be further reduced, and sink marks generated in the thick portion (the vicinity of the maximum thickness portion 21 Ma) of the blade body 21 during forming can be further reduced. Further, the unbalance of the telecentric fan 10E during rotation can be greatly suppressed, and the vibration noise of the telecentric fan 10E can be further reduced.

[ 2 nd modification of the fourth embodiment ]

With reference to fig. 13, a description will be given of a telecentric fan 10F according to a modification 2 of the fourth embodiment. Fig. 13 is an enlarged front view of a part (blade body 21) of the telecentric fan 10F.

The telecentric fan 10F (fig. 13) of the present embodiment differs from the telecentric fans of the embodiments described above in the points where the inner diameter side blades 21M and the outer diameter side blades 21N of the telecentric fan 10F are formed apart from each other.

With the above configuration, the weight of the blade body 21 can be further reduced, and sink marks generated in the thick portion (the vicinity of the maximum thickness portion 21 Ma) of the blade body 21 during forming can be further reduced. Further, the unbalance of the telecentric fan 10F during rotation can be greatly suppressed, and the vibration noise of the telecentric fan 10F can be further reduced.

[ fifth embodiment ]

In the present embodiment, a molding die used for manufacturing the telecentric fan 10 (fig. 1) in the first embodiment, and a blower and an air cleaner using the telecentric fan 10 will be described. The present embodiment can be applied to the telecentric fans of the second to fourth embodiments and the modifications thereof, which are disclosed below.

(Molding die 110)

Fig. 14 is a sectional view showing a molding die 110 used for manufacturing the telecentric fan 10. The molding die 110 includes a fixed die 114 and a movable die 112. A cavity 116 having substantially the same shape as the telecentric fan 10 and into which a fluid resin is injected is defined by the fixed mold 114 and the movable mold 112.

The molding die 110 may be provided with a heater, not shown, for improving the fluidity of the resin injected into the cavity 116. The arrangement of the heater AS described above is particularly effective when a synthetic resin having increased strength such AS a glass fiber-containing AS resin is used.

(blower 120)

Fig. 15 is a sectional view showing a blower 120 using the telecentric fan 10. Fig. 16 is a cross-sectional view showing a cross-sectional shape of blower 120 along line XVI-XVI in fig. 15. Blower 120 includes a drive motor 128 (fig. 16), a telecentric fan 10, and a casing 129 in an outer casing 126.

The output shaft of the driving motor 128 is connected to the shaft sleeve 16 (fig. 16) of the telecentric fan 10. The housing cover 129 has a guide wall 129 a. Guide wall 129a is formed by an approximately 3/4 arc disposed on the outer periphery of telecentric fan 10. The guide wall 129a is formed to increase the speed of the airflow generated by the rotation of the blade body 21 while guiding the airflow in the rotation direction of the blade body 21.

The housing cover 129 is formed with an intake portion 130 (fig. 16) and a blowout portion 127. The suction portion 130 is formed to be located on an extension of the rotary shaft 101. The blowout part 127 is formed so as to open from a part of the guide wall 129a to one side of the tangential direction of the guide wall 129 a. The blowout part 127 is formed in a square tube shape protruding from a part of the guide wall 129a in one tangential direction of the guide wall 129 a.

The telecentric fan 10 is rotated in the direction indicated by the arrow 103 (fig. 15) by the driving of the driving motor 128 (fig. 16). At this time, air is taken into housing 129 from intake 130 and is discharged from inner peripheral space 131 to outer peripheral space 132 of telecentric fan 10. The air sent to the outer peripheral side space 132 flows in the circumferential direction along the direction indicated by the arrow 104, and is blown to the outside by the blowout part 127.

(air cleaner 140)

Fig. 17 is a sectional view showing an air cleaner 140 using the telecentric fan 10. The Air cleaner 140 has a housing 144, a blower 150, a duct 145, and a (HEPA: High Efficiency Particulate Air Filter) screen 141.

The housing 144 has a rear wall 144a and a top wall 144 b. A suction port 142 for sucking air in a room where the air cleaner 140 is installed is formed in the case 144. The suction port 142 is formed in the rear wall 144 a. The housing 144 further has an air outlet 143, and the air outlet 143 discharges clean air into the room. The air outlet 143 is formed in the top wall 144 b. Generally, the air cleaner 140 is installed on a wall side such that the rear wall 144a faces a wall in a room.

The screen 141 is disposed inside the casing 144 so as to face the suction port 142. The air introduced into the casing 144 through the suction port 142 passes through the filter 141 to remove foreign substances, thereby becoming clean air.

The blower 150 sucks indoor air into the casing 144, and sends the air cleaned by the filter 141 through the air outlet 143 into the room. The blower 150 includes the telecentric fan 10, a casing 152, and a drive motor 151. The housing 152 has a guide wall 152 a. The housing 152 has a suction portion 153 and a discharge portion 154.

The duct 145 is provided above the blower 150, and is provided as an air guide path for guiding clean air from the housing 152 to the outlet 143. The duct 145 has a square tube shape with its lower end connected to the blowout part 154 and its upper end opened. The duct 145 is configured to guide the clean air blown out from the blowout part 154 toward the blowout port 143 in a laminar flow.

In the air cleaner 140 having the above-described configuration, the blade body 21 is rotated by the driving of the blower 150, and the indoor air is sucked into the casing 144 through the suction port 142. At this time, an air flow is generated between the suction port 142 and the discharge port 143, and foreign matter such as dust contained in the sucked air is removed by the filter 141.

The clean air obtained through the filter 141 is sucked into the housing 152. At this time, the clean air sucked into the housing 152 is formed into a laminar flow by the guide wall 152a around the blade body 21. The air that has become a laminar flow is guided along the guide wall 152a to the blowout part 154, and is blown from the blowout part 154 into the channel 145. The air is discharged from the blow-out port 143 toward the external space.

According to the air cleaner 140 configured as described above, the power consumption of the driving motor 151 can be reduced by using the telecentric fan 10 having excellent blowing performance. Thus, the air cleaner 140 contributing to energy saving can be realized. Although the present embodiment has been described with reference to an air cleaner as an example, the telecentric fan in each of the embodiments described above may be applied to other devices that send out a fluid, such as an air conditioner (air conditioner), a humidifier, a cooling device, and a ventilator.

For example, when the telecentric fan according to each of the above embodiments is used for a Sirocco fan (Sirocco fan) used in a ceiling-mounted air conditioner or the like, it is possible to improve the performance and reduce the noise. In addition, the noise can be kept constant, the size of the fan can be reduced, and the size of the main body can be reduced. As a result of the miniaturization, a wall-mounted air conditioner can also be installed. The ceiling-mounted air conditioner must be constructed in a large scale, but the wall-mounted room air conditioner can be completed by general construction, and the existing demand is also large. The telecentric fans in the above embodiments may be applied to cross flow fans (cross flow fans) incorporated in wall-mounted room air conditioners.

[ Experimental example ]

Experimental examples carried out in connection with the above embodiments will be described with reference to fig. 18 to 33. In the description, as shown in fig. 18, a straight line connecting the leading edge portion 26 and the trailing edge portion 27 of the blade body 21 is defined as a chord line LN 3. The length of the chord line LN3 is defined as the chord length C. The length of the perpendicular line LN4 at the position P15 where the length of the perpendicular line from the suction surface 24 of the blade body 21 to the chord line LN3 is maximum is defined as the camber t. The camber ratio m is defined as the value of camber t/chord length C.

As shown in fig. 19, a total of 9 types of telecentric fans were prepared as examples 1 to 9. As conditions common to the telecentric fans of experimental examples 1 to 9, the outer diameter of the fan was set to 236mm, the height was set to 80mm, the chord length C of the blade body 21 was set to 20mm, and the minimum thickness of the blade body 21 was set to 1 mm.

(Experimental example 1)

As shown in fig. 19 and 20, in the telecentric fan 10S1 of experimental example 1, the camber t was set to 4.0mm, and the maximum blade thickness was set to 1.0 mm. The camber ratio m (camber t/chord length C) was 0.2, and the thickness ratio, which represents the ratio of the minimum thickness to the maximum thickness, was 1.0.

(Experimental examples 2 to 4)

As shown in fig. 19, in the telecentric fans of experimental examples 2 to 4, the camber t was set to 4.22mm, 4.5mm, and 5.0mm, and the maximum blade thickness was set to 1.55mm, 2.8mm, and 3.15mm, respectively. Camber ratios m (camber t/chord length C) were 0.211, 0.225, 0.25, respectively, and aspect ratios were 1.55, 2.8, 3.15, respectively.

(Experimental example 5)

As shown in fig. 19 and 21, in the telecentric fan 10S5 of experimental example 5, the camber t was set to 5.6mm, and the maximum blade thickness was set to 3.3 mm. The camber ratio m (camber t/chord length C) was 0.28, and the thickness ratio was 3.3.

(Experimental examples 6 to 8)

As shown in fig. 19, in the telecentric fans of experimental examples 6 to 8, the camber t was set to 6.6mm, 7.2mm, and 8.0mm, and the maximum blade thickness was set to 3.46mm, 3.6mm, and 3.67mm, respectively. Camber ratios m (camber t/chord length C) were 0.33, 0.36, 0.4, respectively, and aspect ratios were 3.46, 3.6, 3.67, respectively.

(Experimental example 9)

As shown in fig. 19 and 22, in the telecentric fan 10S9 of experimental example 9, the camber t was set to 8.2mm, and the maximum blade thickness was set to 3.84 mm. The camber ratio m (camber t/chord length C) was 0.41, and the thickness ratio was 3.84.

(relationship between camber ratio m and air flow)

Referring to fig. 19 and 23, the telecentric fans of experimental examples 1 to 9 having the above conditions were rotated at 1250rpm, and the air volume was measured, and the results shown in the table of fig. 19 were obtained. Fig. 23 is a table of the table shown in fig. 19. It is understood that as the camber ratio m increases, the air volume also increases. Considering the increase rate of the air volume, it is preferable that the camber ratio m is 0.25 or more.

(relationship of camber ratio m to noise)

Referring to FIGS. 19 and 24, the air volume of the telecentric fans of the experimental examples 1 to 9 having the above conditions was set to 7.5m³The rotation was carried out in a manner of/min, and the noise was measured, whereby the results shown in the table of FIG. 19 were obtained. Fig. 24 is a table of the table shown in fig. 19. In consideration of the reduction rate of noise, it is also preferable that the camber ratio m be 0.25 or more.

(relationship between camber ratio m and electric power consumption)

Referring to FIGS. 19 and 25, the air volume of the telecentric fans of the experimental examples 1 to 9 having the above conditions was set to 7.5m³The rotation/min was measured for the consumed electric power, and the results shown in the table of fig. 19 were obtained. Fig. 25 is a table of the table shown in fig. 19. In consideration of the reduction rate of the power consumption, it is also preferable that the camber ratio m be 0.25 or more.

(relationship between maximum wing thickness and air flow)

FIG. 26 is a graph showing the relationship between the maximum blade thickness of the test examples 1 to 9 having the above conditions and the air volume obtained when the telecentric fans of the test examples 1 to 9 were rotated at 1250 rpm. It is found that as the maximum wing thickness increases, the air volume increases in a roughly linear relationship.

(relationship between maximum wing thickness and noise)

FIG. 27 shows the maximum wing thickness of the test examples 1 to 9 having the above-mentioned conditions and the air volume of the telecentric fans of the test examples 1 to 9 being 7.5m³Graph of the relationship of the noise generated when rotating in the/min mode. It is found that when the maximum thickness exceeds 2.8mm (experimental example 3 shown in fig. 19), the noise is drastically reduced. It was found that the noise was the smallest when the maximum thickness was 3.6mm (experimental example 7 shown in fig. 19).

(relationship between maximum wing thickness and Power consumption)

FIG. 28 shows the maximum thickness and the average thickness of the test examples 1 to 9 having the above conditionsExperimental examples 1-9 telecentric fans with air volume of 7.5m³Graph of the relationship between the power consumed during the mode rotation of/min. It is found that when the maximum thickness exceeds 3.15mm (experimental example 4 shown in fig. 19), the power consumption is drastically reduced. It is found that the power consumption is the minimum when the maximum thickness is 3.6mm (experimental example 7 shown in fig. 19).

(relationship between wing thickness ratio and air flow)

Fig. 29 is a graph showing the relationship between the blade thickness ratio of experimental examples 1 to 9 having the above conditions and the air volume (relative value) obtained when the telecentric fans of experimental examples 1 to 9 were rotated at 1250 rpm. It is found that as the thickness ratio increases, the air volume increases in a substantially linear relationship.

(relationship of wing thickness ratio to noise)

FIG. 30 shows the blade thickness ratios of the experimental examples 1 to 9 having the above-mentioned conditions, and the air volume of the telecentric fans of the experimental examples 1 to 9 being 7.5m³Graph of the relationship of the noise (relative value) generated when rotating in the mode of/min. It is found that when the thickness ratio exceeds 2.8mm (experimental example 3 shown in fig. 19), the noise is drastically reduced. It is found that the noise is the smallest when the thickness ratio is 3.6mm (experimental example 7 shown in fig. 19).

(relationship between thickness ratio and electric power consumption)

FIG. 31 shows the blade thickness ratios of the experimental examples 1 to 9 having the above-mentioned conditions, and the air volume of the telecentric fans of the experimental examples 1 to 9 being 7.5m³Graph of the relationship between the power consumed during rotation in the/min mode (relative value). It is found that when the thickness ratio exceeds 3.15mm (experimental example 4 shown in fig. 19), the power consumption is drastically reduced. It is found that the power consumption is the minimum when the thickness ratio is 3.6mm (experimental example 7 shown in fig. 19).

(conclusion)

From the results of the above experimental examples 1 to 9, it is understood that a more preferable improvement effect can be obtained if the camber ratio m is 0.25 or more from the viewpoints of an increase in air volume, a reduction in noise, and a reduction in power consumption.

(other examples of experiments)

Fig. 32 is an enlarged front view of a part of telecentric fan 10S7 according to experimental example 7. In the telecentric fan 10S7 of experimental example 7 (fig. 19), the camber t was set to 7.2mm, and the maximum blade thickness was set to 3.6 mm. The camber ratio m (camber t/chord length C) was 0.36, and the thickness ratio was 3.6. According to the telecentric fan 10S7, as shown in fig. 19, the air volume is increased by 8%, the noise is reduced by 1.87dB, and the power consumption is reduced by 6%.

The telecentric fan 10S7a shown in fig. 33 is common to the telecentric fan 10S7 shown in fig. 32 at a point where the camber t is set to 7.2mm, but the maximum blade thickness of the telecentric fan 10S7a is set to 1.0 mm. The camber ratio m (camber t/chord length C) of the telecentric fan 10S7a is 0.36 as with the telecentric fan 10S7, but the thickness ratio of the telecentric fan 10S7a is 1.0. According to the telecentric fan 10S7a, the air volume increases by 4%, the noise increases by 1dB, and the power consumption decreases by 1%.

As is clear from the comparison between the telecentric fans 10S7 and 10S7a, the maximum blade thickness or blade thickness ratio is optimized in addition to the camber ratio m, and thus the air volume can be increased, the noise can be reduced, and the power consumption can be reduced.

While the embodiments, the modifications thereof, and the experimental examples have been described above, the above disclosure is not limited thereto, and is intended to be illustrative in all respects. The technical scope of the present invention is defined by the claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

The contents disclosed in the present specification are industrially applicable to home electric appliances having a blowing function, such as air purifiers and air conditioners.

Description of reference numerals

10. 10A, 10B, 10C, 10D, 10E, 10F, 10S7a, 10S1, 10S5, 10S9, 10S 7: telecentric fan

12. 13: outer peripheral frame

16: shaft sleeve

21: blade body

21A: front blade body

21B: rear blade body

21M: inner diameter side blade part

21 Ma: maximum thickness portion

21 Mb: enlarged part

21 Mc: reduced portion

21N: outer diameter side blade part

21 Np: plate-shaped part

23: airfoil

24. 24A, 24B, 24M, 24 Np: negative pressure surface

24L: length of

24R, 25R: thread

25. 25M, 25 Np: positive pressure noodle

26: front edge part

27: rear edge part

29. 29A, 29B: through hole

29C: gap

29C1, 29C 2: in part

101: rotating shaft

102. 103, 104, H: arrow head

110: molding die

112: movable side mold

114: fixed side mould

116: chamber

120. 150: air blower

127. 154: blowout part

128. 151, 151: driving motor

129. 152: shell cover

129a, 152 a: guide wall

130. 153: suction part

131. 132: space(s)

140: air cleaner

141: filter screen

142: suction inlet

143: blow-out opening

144: shell body

144 a: rear wall

144 b: roof wall

145: channel

AS: containing glass fibers

C: length of wing chord

D: spacer

L1, L2, L3, L4, L5, L6: distance between wings

LN1, LN 2: straight line

LN 3: chord line

LN4, W1, W2: vertical line

P1, P3, P4, P5, P6: location of a body part

P2: site (maximum thickness position)

P10, P11, P12: dot

P13, P15: position of

WA, WB: speed of rotation

h1, h3, h4, h5, h 6: wing thickness

h 2: maximum thickness

m: camber ratio

t, t1, t 2: camber

Claims

1. A telecentric fan is characterized in that the telecentric fan comprises a plurality of blade bodies, wherein the blade bodies are provided with a front edge part for air inflow and a rear edge part for air outflow and are arranged at intervals in the circumferential direction;

a plurality of blade bodies each having an airfoil surface extending between the leading edge portion and the trailing edge portion and including a positive pressure surface on a side of the blade body in a rotational direction and a negative pressure surface on an opposite side of the blade body in the rotational direction;

the plurality of blade bodies include a front-side blade body and a rear-side blade body that faces the front-side blade body with the gap therebetween and is located on the opposite side in the rotational direction from the front-side blade body;

if the shortest distance from any portion on the negative pressure surface of the front blade body to the positive pressure surface of the rear blade body is defined as the inter-blade distance in the portion,

the front blade body has a maximum thickness portion that specifies a maximum thickness among the front blade bodies, and a position on a negative pressure surface in the maximum thickness portion is defined as a maximum thickness position,

defining a range between the maximum thickness position and the leading edge portion among the suction surfaces of the leading blade body as an inner diameter side suction surface,

defining a range between the maximum thickness position and the trailing edge portion among the suction surfaces of the front blade body as an outer diameter side suction surface,

defining a length from the leading edge portion to the trailing edge portion in a negative pressure surface of the leading blade body as a negative pressure surface length, then

The inter-blade distance in the inner diameter side negative pressure surface is longer than the inter-blade distance at the maximum thickness position,

the distance between the blades in the range between the maximum thickness position and a position away from the maximum thickness position by at least half of the length of the suction surface is substantially constant in the outer diameter side suction surface.

2. The telecentric fan of claim 1,

each of the plurality of blade bodies includes an inner diameter side blade portion including the leading edge portion, and an outer diameter side blade portion located radially outward of the inner diameter side blade portion and including the trailing edge portion;

the inner diameter side blade portion includes:

a maximum thickness portion that defines a maximum thickness among the inner diameter side blade portions;

an enlarged portion located between the leading edge portion and the maximum thickness portion, the enlarged portion gradually increasing in thickness from the leading edge portion side toward the radially outer side; and

a reduced portion located radially outward of the maximum thickness portion, the reduced portion gradually decreasing in thickness from the maximum thickness portion side toward the radially outward side;

a negative pressure surface of the inner diameter side blade and a positive pressure surface of the inner diameter side blade each having a surface shape curved in a convex shape toward the opposite side of the rotation direction;

a curvature of a negative pressure surface of the inner diameter side blade portion is larger than a curvature of a positive pressure surface of the inner diameter side blade portion;

the outer diameter side blade section includes a plate-shaped section extending from the trailing edge section side to the radially inner side with substantially the same blade thickness;

the curvature of the negative pressure surface of the plate-shaped portion and the curvature of the positive pressure surface of the plate-shaped portion are both smaller than the curvature of the negative pressure surface of the inner diameter side blade portion.

3. A telecentric fan according to claim 2, wherein the positive pressure surface of the inner diameter side blade portion and the positive pressure surface of the outer diameter side blade portion are tangent to each other,

the suction surface of the inner diameter side blade and the suction surface of the outer diameter side blade are tangent to each other.

4. A telecentric fan according to claim 2 or 3, wherein the maximum thickness of the outer diameter side blade portion is less than the maximum thickness of the inner diameter side blade portion;

the camber of the outer diameter side blade portion is smaller than the camber of the inner diameter side blade portion.

5. A telecentric fan according to claim 4, wherein the inner diameter side blade portion is provided with a through hole extending in a direction parallel to the rotation axis;

the through-hole may be formed to include the maximum thickness portion, or may be formed to be one each on the inside in the radial direction and the outside in the radial direction of the maximum thickness portion.

6. A telecentric fan according to claim 5, wherein the inner peripheral surface of the inner-diameter-side blade portion in which the through-hole is formed is in a brow shape when viewed from a direction parallel to the rotation axis.

7. Telecentric fan according to claim 6, wherein if the straight line connecting the front edge and the rear edge is defined as a chord line,

the length of the chord line is C, the length of the perpendicular line that extends from the suction surface of the blade body to the position where the length of the perpendicular line extending from the suction surface of the blade body to the chord line is maximum is t, and the value of t/C is defined as a camber ratio m

Each of the plurality of blade bodies is formed so that the camber ratio m is 0.25 or more.

8. The telecentric fan of claim 7, wherein said plurality of blade bodies are configured as rows of constant velocity airfoils.

9. A telecentric fan according to claim 8, wherein the telecentric fan is formed from a resin.

10. A molding die for molding a telecentric fan according to claim 9.

11. A fluid transport apparatus comprising a blower including the telecentric fan according to any one of claims 1 to 9 and a drive motor coupled to the telecentric fan and configured to rotate the plurality of blade bodies.